I can't seem to reproduce this issue. Have you made any modifications to the source?

Could you please run "cat include/classes/core/ZBase.php | grep /include/" from the frontend directory and show us the output? This will make sure that all files are included correctly.

I have not made any modifications to the source.

cat include/classes/core/ZBase.php | grep /include/
require_once $this->getRootDir().'/include/debug.inc.php';
require_once $this->getRootDir().'/include/gettextwrapper.inc.php';
require_once $this->getRootDir().'/include/defines.inc.php';
require_once $this->getRootDir().'/include/func.inc.php';
require_once $this->getRootDir().'/include/html.inc.php';
require_once $this->getRootDir().'/include/perm.inc.php';
require_once $this->getRootDir().'/include/audit.inc.php';
require_once $this->getRootDir().'/include/js.inc.php';
require_once $this->getRootDir().'/include/users.inc.php';
require_once $this->getRootDir().'/include/validate.inc.php';
require_once $this->getRootDir().'/include/profiles.inc.php';
require_once $this->getRootDir().'/include/locales.inc.php';
require_once $this->getRootDir().'/include/db.inc.php';
require_once $this->getRootDir().'/include/nodes.inc.php';
require_once $this->getRootDir().'/include/acknow.inc.php';
require_once $this->getRootDir().'/include/actions.inc.php';
require_once $this->getRootDir().'/include/discovery.inc.php';
require_once $this->getRootDir().'/include/draw.inc.php';
require_once $this->getRootDir().'/include/events.inc.php';
require_once $this->getRootDir().'/include/graphs.inc.php';
require_once $this->getRootDir().'/include/hosts.inc.php';
require_once $this->getRootDir().'/include/httptest.inc.php';
require_once $this->getRootDir().'/include/ident.inc.php';
require_once $this->getRootDir().'/include/images.inc.php';
require_once $this->getRootDir().'/include/items.inc.php';
require_once $this->getRootDir().'/include/maps.inc.php';
require_once $this->getRootDir().'/include/media.inc.php';
require_once $this->getRootDir().'/include/services.inc.php';
require_once $this->getRootDir().'/include/sounds.inc.php';
require_once $this->getRootDir().'/include/triggers.inc.php';
require_once $this->getRootDir().'/include/valuemap.inc.php';
$this->rootDir.'/include/classes',
$this->rootDir.'/include/classes/core',
$this->rootDir.'/include/classes/api',
$this->rootDir.'/include/classes/db',
$this->rootDir.'/include/classes/debug',
$this->rootDir.'/include/classes/validators',
$this->rootDir.'/include/classes/validators/schema',
$this->rootDir.'/include/classes/validators/string',
$this->rootDir.'/include/classes/validators/object',
$this->rootDir.'/include/classes/validators/hostgroup',
$this->rootDir.'/include/classes/validators/host',
$this->rootDir.'/include/classes/validators/hostprototype',
$this->rootDir.'/include/classes/validators/event',
$this->rootDir.'/include/classes/export',
$this->rootDir.'/include/classes/export/writers',
$this->rootDir.'/include/classes/export/elements',
$this->rootDir.'/include/classes/import',
$this->rootDir.'/include/classes/import/importers',
$this->rootDir.'/include/classes/import/readers',
$this->rootDir.'/include/classes/import/formatters',
$this->rootDir.'/include/classes/items',
$this->rootDir.'/include/classes/server',
$this->rootDir.'/include/classes/screens',
$this->rootDir.'/include/classes/sysmaps',
$this->rootDir.'/include/classes/helpers',
$this->rootDir.'/include/classes/helpers/trigger',
$this->rootDir.'/include/classes/macros',
$this->rootDir.'/include/classes/tree',
$this->rootDir.'/include/classes/html',
$this->rootDir.'/include/classes/parsers',
require_once $this->getRootDir().'/include/translateDefines.inc.php';

I mentioned this problem on the irc channel and Richlv said:
14:09 Richlv> peterb_, well, in trunk maps seem to be complete broken for me
Perhaps he can give more info.

I have installed zabbix 2.2.2 on a test server, run the above command and there the next line IS included:
require_once $this->getRootDir().'/include/maintenances.inc.php';

The 2.2.0 installation we have is from the official zabbix repo.

Yes, looks like the package you've installed is missing this line.

    require_once $this->getRootDir().'/include/maintenances.inc.php';

What package did you install exactly?

Installed version 2.2.0-1.el6 from the zabbix repository:

$ yum list installed | grep zabbix
fping.x86_64 2.4b2-16.el6 @zabbix-non-supported
libssh2.x86_64 1.4.2-2.el6 @zabbix-non-supported
zabbix.x86_64 2.2.0-1.el6 @zabbix
zabbix-agent.x86_64 2.2.0-1.el6 @zabbix
zabbix-get.x86_64 2.2.0-1.el6 @zabbix
zabbix-java-gateway.x86_64 2.2.0-1.el6 installed
zabbix-release.noarch 2.2-1.el6 @zabbix
zabbix-sender.x86_64 2.2.0-1.el6 @zabbix
zabbix-server.x86_64 2.2.0-1.el6 @zabbix
zabbix-server-mysql.x86_64 2.2.0-1.el6 @zabbix
zabbix-web.noarch 2.2.0-1.el6 @zabbix
zabbix-web-mysql.noarch 2.2.0-1.el6 @zabbix

Thanks for all the information. This file is indeed included incorrectly in the RHEL 2.2.0 package. I'll reassign the issue to Kodai, our RHEL package manager, to fix the package. But as for now you can use the attached patch to fix the problem.

The maintenance.patch is incorrect.

The correct is maintenances.inc.php (plural), not maintenance.inc.php (singular).

Frederico Passos, right, my mistake. I've corrected the patch.

Fixed in 2.2.3